An inertia cone crusher may be utilized for efficient crushing of material, such as stone, ore, etc. into smaller sizes. An example of an inertia cone crusher can be found in RU 2 174 445. In such an inertia cone crusher, material is crushed between an outer crushing shell, which is mounted in a frame, and an inner crushing shell, which is mounted on a crushing head which is supported on a spherical bearing. The crushing head is mounted on a crushing shaft. An unbalance weight is arranged on a cylindrical sleeve encircling the crushing shaft. The cylindrical sleeve is, via a drive shaft, connected to a pulley. A motor is operative for rotating the pulley, and, hence, the cylindrical sleeve. Such rotation causes the unbalance weight to rotate and to swing to the side, causing the crushing shaft, the crushing head, and the inner crushing shell to gyrate and to crush material that is fed to a crushing chamber formed between the inner and outer crushing shells.